chore: cover code coverage

[pmakani]

Thank you for opening a Pull Request! Before submitting your PR, there are a few things you can do to make sure it goes smoothly:

• Make sure to open an issue as a bug/issue before writing your code! That way we can discuss the change, evaluate designs, and agree on the general idea
• Ensure the tests and linter pass
• Code coverage does not decrease (if any source code was changed)
• Appropriate docs were updated (if necessary)

Fixes #330

[codecov]

Codecov Report

Merging #395 into master will increase coverage by 3.47%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##             master     #395      +/-   ##
============================================
+ Coverage     77.88%   81.36%   +3.47%     
- Complexity     1184     1225      +41     
============================================
  Files            77       77              
  Lines          6218     6218              
  Branches        691      691              
============================================
+ Hits           4843     5059     +216     
+ Misses         1021      802     -219     
- Partials        354      357       +3     

Impacted Files	Coverage Δ	Complexity Δ
...y/src/main/java/com/google/cloud/bigquery/Job.java	86.33% <0.00%> (+0.71%)	32.00% <0.00%> (+1.00%)
...ain/java/com/google/cloud/bigquery/QueryStage.java	96.57% <0.00%> (+1.02%)	40.00% <0.00%> (+1.00%)
...main/java/com/google/cloud/bigquery/ModelInfo.java	78.48% <0.00%> (+1.26%)	25.00% <0.00%> (+1.00%)
...c/main/java/com/google/cloud/bigquery/Routine.java	81.13% <0.00%> (+1.88%)	12.00% <0.00%> (+1.00%)
...main/java/com/google/cloud/bigquery/RoutineId.java	74.07% <0.00%> (+3.70%)	14.00% <0.00%> (+1.00%)
...ava/com/google/cloud/bigquery/RoutineArgument.java	90.90% <0.00%> (+4.54%)	5.00% <0.00%> (ø%)
...om/google/cloud/bigquery/LoadJobConfiguration.java	93.20% <0.00%> (+5.66%)	56.00% <0.00%> (+4.00%)
...src/main/java/com/google/cloud/bigquery/Table.java	86.58% <0.00%> (+9.75%)	23.00% <0.00%> (ø%)
...m/google/cloud/bigquery/QueryJobConfiguration.java	90.08% <0.00%> (+12.12%)	66.00% <0.00%> (+8.00%)
...n/java/com/google/cloud/bigquery/BigQueryImpl.java	83.59% <0.00%> (+16.75%)	74.00% <0.00%> (+17.00%)
... and 2 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 57982a0...10f1934. Read the comment docs.